1. Field of the Invention
The present invention relates to an image processing apparatus and an image processing method, and in particular, relates to an image retargeting technique for stereo images.
2. Description of the Related Art
Recently, image display systems have become diversified in their sizes from small-size monitors such as PDA and mobile phones to large-screen displays, depending on applications. With this diversification, a simple reduction of an image without consideration of a resolution difference etc. may lose the impression of the image or necessary visual information; accordingly, the automatic/semiautomatic size change of content images has become a critical issue. The modification associated with the diversification of displays becomes a more critical issue in three-dimensional displays. In the modification of stereo images, since the parallax value between the positions of objects in the images indicates the depth, it becomes necessary to satisfy the consistency between the images, so that the constraint condition becomes much severer than that of the modification of two-dimensional images.
In view of such circumstances, studies are proceeding with context-aware image processing in consideration of important parts in the image in observation by human beings particularly as a technique for modifying two-dimensional image contents. This processing includes simple processing of cropping important parts and the automatic change of the composition with significant elements left. Among them, processing for changing the horizontal to vertical ratio while maintaining the shapes of important objects is called image retargeting. A technique called seam-carving is advocated as one of the image retargeting techniques (see AVIDAN, S., AND SHAMIR, A. 2007. Seam carving for content-aware image resizing. ACM Trans. Graph. 26, 3, Article No. 10).